Long operating life, fuel efficiency, passenger safety and customer satisfaction - all important considerations in the transportation industry - rely heavily on precision alignment of body parts and operating components. In recent years, lasers and laser sensors have become integral parts of robot guidance systems that facilitate and optimize production, particularly for automotive and aircraft bodies. By the early 1980s, US automakers were incorporating laser technology into the body assembly process. In seconds, noncontact laser-based machine vision tracked body-to-body variation from several key dimensional control points. Manufacturers were able to compare real data to design intent by using large volumetric calibration and coordinate space realignment. Space transformation algorithms formed the basis for Robot guidance systems got their start finding a better way to insert front windshields on light trucks in a single plant. The new system instructed the robot to pick up a windshield, locate the opening on the vehicle and insert the part with unmatched precision. Laser-based robot guidance systems rapidly became the plant standard for automatic glass decking cells, for rear glass insertion, for seam sealant and for stud welding. Today hundreds of assembly facilities are using the systems to greatly reduce cycle times and fixturing and material costs, and to enhance ergonomic conditions.